Sennheiser evolution wireless problem
 

I just bought EW112P camera Mountable lav, now there is one problem. I only can received from one channel, so does any one have the similar problem? Or I just mess something wrong.

EW112P
 

Sakura,

I am jumping into this not knowing what camera you have or what you actually bought but...

I believe that is a mono microphone, only one channel of output from the receiver.

Are you plugging the receiver into a stereo jack? If so, then you will still only get one channel.

When I need to run wireless I run on EW112P into the left channel and another EW112P into the right channel on a Sony PD-150.

Hope this helps!

Sakura,

Ottotune is right...it'll be better to head this off from becoming a guessing match and to give you more accurate suggestions by getting more info first. Can you give us a bit more info?

I think I bought ME2 clip-on micoophone with all other wireless set. The camcorder I am using is Canon XL1. I tried to use RCA both right and left channel to connect mini jack plug which was used for ME2 clip-on mic. I think what I used is stereo jack plug.

Do it in post.
 

You could have a problem with stereo adapter. Try switching the plugs around and see if it follows the plug channel.

The best way to get around this problem is to fix in post. Just copy whatever channel the audio is on to the other channel. This frees the other channel for another audio source during production.

I was just talking to an engineer about this today. It has something to do with the output being balanced or unbalnaced. He told me that an unbalnced output (like the EW112P) will not give you a stereo signal. This may be some of your problem, and I'm sorry I can't explain more, but this "teknikal stuff" is over my head. But if you keep having problems then talk to someone about the balanced or unbalnaced output. I just ordered a EW112P today, this is why this conversation came up. But he also told me that most mics are unbalnced so I wasn't getting any less of a mic system that is out there now. Hope this helps or probably jsut confused you more.

Balance does not mean stereo.
 

Kelly,

It is true that the EW112p is an unbalance system. That has nothing to do with the fact that the mic is also monaural. The balance that the engineer was refering to has to do with the signal out of a balanced mic system.

Microphone cables can act like antennas. By using balanced cables reduces the noise from this noise. Since the noise is impressed across the conductors in the balanced system, the system is designed to reject this. Audio from the mic, however, is not rejected.

Again the best way to get the audio to both channels of a camcorder from a mono mic is to fix it in post with your editing package.

Happy Holidays,

Nate,
Gotcha. Like I said, this stuff is way beyond me. I should just shut up and keep pointing and shooting. Thanks for the help, I am slowly learning much about all this stuff.
Kelly

Not a problem Kell. Its pretty hard to find a book about all this stuff at the grocery store.

Happy Holidays,

I'll try to take your understanding of balanced and unbalanced lines one step further:

In a balanced system, the audio is split into two signals. One of the signals is inverted... meaning that each signal is 180 degrees out of phase... meaning that when one signal goes up in amplitude, the other is going down.

Any noise that the mic cable picks up will be the same across both conductors. A positive spike on one conductor will also have a positive spike on the other.

When the two signals are remixed (in the camera, or mixer, or recorder) the inverted signal is brought back into phase. The noise spikes, however, are now out of phase... and consequently cancel each other out when the two signals are blended back together. It's a fairly simple, yet very effective concept.

Your engineer friend was also off base on the number of mics that are balanced versus unbalanced. There are WAY more balanced mics than unbalanced ones... at least in regards to professional mics. They are easy to spot... they're the ones with THREE conductors, usually with XLR connectors.

For those that are interested in microphones, you can learn a great deal from people like Harvey Gerst on bbs's like homerecording.com.

On a separate note, it may be possible to setup your XL1s to record both channels from one input (I can on my PD150), but since I don't own the Canon... I could be wrong.

Hope this helps.

Mono E Mono
 

I just got the expensive MA300 (cheap plastic) mic adapter from Canon for my GL2, it has the same setup; two mono inputs, I was thinking about making a cable to feed both inputs from my shotgun, but thought I'd be better off using the second input for a wireless or handheld mic, that way I have a couple of tracks to select from in post if nessassary, it's easier to chuck unwanted stuff than reshoot (see my Denali clip feedback :) The copy and paste method is a great way so solve stereo imaging problems in post and you can slip the second track a few samples and it will fatten up a thin track if needed, be careful though, a little slip goes a long way.

Also thanks to Doug Quance for the great explantion of balanced v. unbalanced it's a simple concept that is hard to explain as simply as he did, great job.
my 2 cents

Microphones
 

the description of "phase cancellation" is an accurate one, and it is the feature that makes balanced audio systems far more desirable than unbalances ones....the result of going balanced is:
longer runs with xlr cables
lower over all noise
resistance to RF
resistance to 60 cycle hum
a few additionl tips....
when running audio cables, never run PARALLEL to AC cables
especially if closer than 7 or 8 inches, even balanced cables may pick up 60 cycle hum....better to cross PERPENDICULAR to ac if you need to cross the cables, and obviously never snake audio and power cables together.
be careful of microphone placement...phase cancellation can also cause your audio to sound weak and thin, having the same cancellation effect as the hum reduction in your cables.....avoid close proximity, and check mic placement...usually right angles produce the best results with cardiod mics.....omnis will be tougher to deal with
finally, on a slightly different note, avoil hum induced by ground loops by powering all devices in a chain by the same breaker.